(a) Let the percentage of 17X 37 is p
Percentage of 17X 35 = (100 – p)
Average atomic weight = 35.5
Therefore
35.5 = 37p + 35(100 − p) /100
3550 = 37p + 3500 − 35p
3550 – 3500 = 37p - 35p
2p = 50 ⇒ p = 25%
Therefore, sample of 17X 37 is 25% and 17X 35 will be 100 – 25 = 75%
(b) Cesium 137 – Used to treat cancerous tumors. Calcium 47 – It is an important aid for biomedical researchers studying the cellular functions